My observation: the cheapest "quality multiplier" is forcing question structure (context, expected vs actual, repro steps, minimal snippet, what you tried).

If you could add only ONE mechanism to keep Q&A quality high long-term, what would it be?

stricter question templates / guardrails reputation incentives stronger moderation / review queues rate limits / anti-spam something else?

I'm collecting opinions from experienced devs and will build the top suggestion into an experiment.